我有一个简单的Java记录,其中Address类使用传统的POJO。序列化按预期工作,但反序列化失败,并显示错误消息"Cannotsetfinal"
public record TestRecord(String name, @JsonUnwrapped Address address) {}
序列化这个工作正常。
Address address = new Address();
address.setCity("New York");
address.setState("NY");
TestRecord rec = new TestRecord("Bob", address);
JsonMapper jsonMapper = new JsonMapper();
jsonMapper.writeValueAsString(rec); // {"name":"Bob","city":"New York","state":"NY"}
但是反序列化会抛出一个异常:
@Test
void should_DeserializeUnwrappedRecord() throws JsonProcessingException {
Address address = new Address();
address.setCity("New York");
address.setState("NY");
TestRecord expectedRecord = new TestRecord("Bob", address);
String json = """
{"name":"Bob","city":"New York","state":"NY"}""";
JsonMapper jsonMapper = new JsonMapper();
TestRecord actualValue = jsonMapper.readValue(json, TestRecord.class);
assertEquals(expectedRecord, actualValue);
}
例外情况:
com.fasterxml.jackson.databind.JsonMappingException: Can not set final org.example.AppTest$Address field org.example.AppTest$TestRecord.address to org.example.AppTest$Address
at [Source: UNKNOWN; byte offset: #UNKNOWN]
at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:276)
Caused by: java.lang.IllegalAccessException: Can not set final org.example.AppTest$Address field org.example.AppTest$TestRecord.address to org.example.AppTest$Address
at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwFinalFieldIllegalAccessException(UnsafeFieldAccessorImpl.java:76)
at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwFinalFieldIllegalAccessException(UnsafeFieldAccessorImpl.java:80)
at java.base/jdk.internal.reflect.UnsafeQualifiedObjectFieldAccessorImpl.set(UnsafeQualifiedObjectFieldAccessorImpl.java:79)
at java.base/java.lang.reflect.Field.set(Field.java:799)
如果我将TestRecord更改为一个普通的Java类,它可以正常工作。
1条答案
按热度按时间nuypyhwy1#
TestRecord
是一个记录,这意味着它的所有字段都是final。因此,您可以使用默认配置将JSON反序列化到此对象。我认为你有两个选择:
1.使用JsonProperty标记每个字段
1.使用以下项更改Jackson的字段可见性级别: